Assigning an array of values as the type of variable

[hwndmaster]

Briefly

I have a scenario where I need:

• to have an sensor helper or variable that would live during the uptime of HA, which may contain an array of string values.
• to be able to add new items to the array.
• to be able to remove items from array, if there are more than X items.
• to render the item values in a card. For now I'm using Markdown Card with a template which enumerates all the values and renders them in the card.

From other issues of the repository I understand that the add-on supports any type of JSON-like objects, like strings, dictionaries, etc. So I expected to have arrays also supported by the add-on, correct me if I'm wrong.

To reproduce

Here is the variable definition in configuration.yaml:

var:
  example_array:
    friendly_name: "Example Array"
    initial_value: []
    icon: mdi:view-list-outline

Then I'm attempting to set a value to that array variable using the Developer tools / Actions:

action: var.set
data:
  entity_id: var.example_array
  value_template: >-
    {{
      [1, 2, 3]
    }}

This doesn't work with an error reported:

Caution

Failed to perform the action var.set. template value should be a string for dictionary value @ data['value_template']. Got None

I've attempted to assign an array to an attribute, same issue.

If I try to assign an array using value parameter, then it seems it is being assigned as a string. Here is the script:

action: var.set
data:
  entity_id: var.example_array
  value: [1, 2, 3]

Then I validated it with Developer tools / Template:

{% if [1,2,3] is list %}
  [1,2,3] is a list.
{% endif %}
{% if states('var.example_array') is list %}
  var.example_array is a list.
{% endif %}
{% if states('var.example_array') is string %}
  var.example_array is a string.
{% endif %}

It renders only:

  [1,2,3] is a list.
  var.example_array is a string.

Could someone help me to understand how to work with arrays correctly?
Thanks.

[hwndmaster]

I forgot to mention, that I've attempted to use data_template as well, such as:

action: var.set
data_template:
  entity_id: var.example_array
  value_template: >-
    {{ [1, 2, 3] }}

action: var.set
data_template:
  entity_id: var.example_array
  value: [1,2,3]

action: var.set
data_template:
  entity_id: var.example_array
  value: "{{ [1,2,3] }}"

The result is all the same.